1. Field of Invention
This invention relates to a liquid crystal device and to a projection display device using the liquid crystal device.
2. Description of Related Art
A projection display device can be used to display a computer image and a television image. The projection display device modulates a light beam emitted from a light source with an electro-optical device called a light valve, and projects the modulated light beam onto a screen to display an image. A liquid crystal device is usually used as the light valve of such a projection display device.
The projection display device is usually provided with a cooling fan, and the liquid crystal device is cooled by a flow of air generated by the cooling fan. However, since dust is often included in air, the dust may adhere to the surface of the liquid crystal device. When the dust adheres to the surface of the liquid crystal device, a shadow of the adhered dust is projected, such that the quality of an image displayed by the projection display device is deteriorated.